Linux as Bootloader

Linux as Bootloader

[Christian Gmeiner]

Hi all,

I am using the linux kernel in combination with busybox and a separate
bootloader app to
startup a x86 based embedded device. As the used BIOS does only do
basic hw init, we
used Linux as a bootloader. Our custom BIOS starts the bootloader
kernel located in BIOS
flash. If the kernel and userland is ready our boot application
searches for the productive kernel
and executes it via kexec.

Now I run in some troubles as I need to be able to boot a MSDOS
application stored on
an usb stick. I have tried grub4linux but I am not able to boot from
the usb stick - even I
see the grub command line.

Are there some creative/working solutions for my problem?

thanks
--
Christian Gmeiner, MSc

Re: Linux as Bootloader

[el es]

Christian Gmeiner <christian.gmeiner <at> gmail.com> writes:

> 
> Hi all,
[...]
> Now I run in some troubles as I need to be able to boot a MSDOS
> application stored on
> an usb stick. [...]
> Are there some creative/working solutions for my problem?
> 

How about some DOS emulator (e.g. DosEmu or DosBox) (if you really
have to run DOS program(s) and absolutely can't recompile/rewrite it for 
Linux...) - but if you need low-level hw access I think you'd better
create a kernel module...

> thanks
> --
> Christian Gmeiner, MSc
> 

L.

Re: Linux as Bootloader

[Eric W. Biederman]

Christian Gmeiner <christian.gmeiner@gmail.com> writes:

> Hi all,
>
> I am using the linux kernel in combination with busybox and a separate
> bootloader app to
> startup a x86 based embedded device. As the used BIOS does only do
> basic hw init, we
> used Linux as a bootloader. Our custom BIOS starts the bootloader
> kernel located in BIOS
> flash. If the kernel and userland is ready our boot application
> searches for the productive kernel
> and executes it via kexec.
>
> Now I run in some troubles as I need to be able to boot a MSDOS
> application stored on
> an usb stick. I have tried grub4linux but I am not able to boot from
> the usb stick - even I
> see the grub command line.
>
> Are there some creative/working solutions for my problem?

There has been some success using a modified bochs bios on real hardware
in the context of coreboot.  That should be loadable from linux and
usable on your setup.  Avoiding the DOS requirement is probably a more
certain path, getting DOS going is probably more fun.

Eric

Re: Linux as Bootloader

[Geoff Levand]

Hi Christian,

On 09/05/2011 01:24 AM, Christian Gmeiner wrote:
> I am using the linux kernel in combination with busybox and a separate
> bootloader app to
> startup a x86 based embedded device.

Just FYI, Petitboot, a kexec base bootloader, does the same
thing as what you have done.

I'm now working on adding a twin GUI program and an x86 OpenWRT build.

Current info is here:

  http://www.kernel.org/pub/linux/kernel/people/geoff/petitboot/
  http://git.kernel.org/?p=linux/kernel/git/geoff/petitboot.git

Some old info is here:

  http://www.kernel.org/pub/linux/kernel/people/geoff/cell/ps3-petitboot/
  http://ozlabs.org/~jk/projects/petitboot/

-Geoff

Re: Linux as Bootloader

[James Courtier-Dutton]

On 5 September 2011 09:24, Christian Gmeiner
<christian.gmeiner@gmail.com> wrote:
> Hi all,
>
> I am using the linux kernel in combination with busybox and a separate
> bootloader app to
> startup a x86 based embedded device. As the used BIOS does only do
> basic hw init, we
> used Linux as a bootloader. Our custom BIOS starts the bootloader
> kernel located in BIOS
> flash. If the kernel and userland is ready our boot application
> searches for the productive kernel
> and executes it via kexec.
>
> Now I run in some troubles as I need to be able to boot a MSDOS
> application stored on
> an usb stick. I have tried grub4linux but I am not able to boot from
> the usb stick - even I
> see the grub command line.
>
> Are there some creative/working solutions for my problem?
>

To get DOS running, it relies on a PC BIOS. You don't have one.
Either implement a PC BIOS or run the dos app using dosbox, dosemu or kvm.
Just out of curiosity, what does the DOS app do?
There might be a reason why running it in dosbox, dosemu, or kvm might not work.

Re: Linux as Bootloader

[Christian Gmeiner]

Hi Geoff,


2011/9/11 Geoff Levand <geoff@infradead.org>:
> Hi Christian,
>
> On 09/05/2011 01:24 AM, Christian Gmeiner wrote:
>> I am using the linux kernel in combination with busybox and a separate
>> bootloader app to
>> startup a x86 based embedded device.
>
> Just FYI, Petitboot, a kexec base bootloader, does the same
> thing as what you have done.
>
> I'm now working on adding a twin GUI program and an x86 OpenWRT build.
>
> Current info is here:
>
>  http://www.kernel.org/pub/linux/kernel/people/geoff/petitboot/
>  http://git.kernel.org/?p=linux/kernel/git/geoff/petitboot.git
>

Petitboot sounds nice, but kernel.org is down. Is there an other way to get
access to it via git?

> Some old info is here:
>
>  http://www.kernel.org/pub/linux/kernel/people/geoff/cell/ps3-petitboot/
>  http://ozlabs.org/~jk/projects/petitboot/
>
> -Geoff
>

thanks
--
Christian Gmeiner, MSc

Re: Linux as Bootloader

[Geoff Levand]

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Hi Christian,

On 09/16/2011 04:02 AM, Christian Gmeiner wrote:
> 2011/9/11 Geoff Levand <geoff@infradead.org>:
>> Just FYI, Petitboot, a kexec base bootloader, does the same
>> thing as what you have done.
>>
>> Current info is here:
>>
>>  http://www.kernel.org/pub/linux/kernel/people/geoff/petitboot/
>>  http://git.kernel.org/?p=linux/kernel/git/geoff/petitboot.git
> 
> Petitboot sounds nice, but kernel.org is down. Is there an other way to get
> access to it via git?

I put a mirror of the current repo at infradead.org:

  http://git.infradead.org/users/geoff/petitboot.git

I'm still working on the twin GUI support, so don't have it
merged in yet.  I also have a hand full of bug fixes I need
to merge.

-Geoff 

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Re: Linux as Bootloader

[Geoff Levand]

Hi Christian,

On 09/16/2011 04:02 AM, Christian Gmeiner wrote:
> 2011/9/11 Geoff Levand <geoff@infradead.org>:
>> On 09/05/2011 01:24 AM, Christian Gmeiner wrote:
>>> I am using the linux kernel in combination with busybox and a separate
>>> bootloader app to
>>> startup a x86 based embedded device.
>>
>> Just FYI, Petitboot, a kexec base bootloader, does the same
>> thing as what you have done.
>>
>> I'm now working on adding a twin GUI program and an x86 OpenWRT build.
> 
> Petitboot sounds nice, but kernel.org is down. Is there an other way to get
> access to it via git?

Just FYI, my petitboot repo at kernel.org is back:

  http://git.kernel.org/?p=linux/kernel/git/geoff/petitboot.git

Also, I put a preliminary version of new Web pages I'm
working on here:

  http://bombadil.infradead.org/~geoff/petitboot/

-Geoff